Crankshaft blank



A 16, 1940. w. FLG-ROVENE I cnmsam Bum;

Original filed-W24, 1958 v win/Essiv v V INVENTORS VwLLlAM F-GROEHER BYAL ER R.METE

V V ATTORNEY.

Patented A r. 16.1940. 1

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Machine Tool Company, Cincinnati, Ohio, a corporation of Delaware 7Original application May 24, 1938, Serial N6.

209,738. Divided and this application November 21, 1938, SerialNo.241,486-

a claims. (01. 29-148) This application is a division of our copendingapplication, Serial Number 209,738 filed May 24,

This invention pertains to the preparation of crankshafts for chuckingand loading and unloading them in lathes formachining the variousbearing portions of said crankshafts. More particularly this inventionis related to the prepara-' tion of locating areas on a rough crankshafti0 forging or casting for chucking and to facilitate loading andunloading the crankshaft in the lathe without the use of loading devicesof any kind. Specifically this invention consists of providing a uniquearrangement of locating areas on the webs of the roughcra'nkshaft'forging or casting by which said shaft is loaded andunloaded and chucked for turning in a center drive type of lathe of acharacter shown in Patent 2,069,107 dated January 26,-193'7, in whichthe 2) crankshaft is chucked and rotated by means of one or more centerdrive chucks and has its ends supported by centers while cutting toolsoperate on the various bearing portions of said crankshaft. v

g5 Heretofore in lathes of this character it has always been a majordifliculty to provide proper means to load and unload the crankshaftinto the center drive chucks. One difiiculty has been that caused by thetailstock each side of the cen- 30 ter drive chucks which prevented theinsertion and removal of I the work in the center drive chuck on theaxis of rotation of the chuck and crankshaft. In order, to avoid movingthe tailstocks it was found necessary to make the cen- 5 ter drive gearsrelatively large in diameter, in fact so large as to make the machinedifficult to operate as these large center drive gears necessitatedlarge housings which projected outwardly to the front of the machine andinterfered with 40 the operator's access to the cutting tools andchucking mechanism in the ring gears. In fact these ring gears became solarge in instances where loading devices were used that it waspractically impossible for the operator to get at 5 certain of thetools, and also diiliculty was found in gaining access to the variousclamping devices in the ring gear chucks. Another defect ofv the largering gears was the difficulty in presenting the tools to the work fromsuch a far removed 50 position when the ring gears were so large as-v toprevent putting the tool supporting devices sufficiently close to thework piece being machined for proper stability of the tools. This largering gear construction also presented much 55 greater expense inmanufacture, particularly in instances where anti-friction bearings orother highly expensive bearings of large diameter were required. Andalso in cases where plain bearings were used in conjunction with theselarge ring gears the surface velocity of the bearing surfaces 6necessary to properly rotate thecrankshaft at cutting speed were so highas to create serious problems of lubrication and wear in the bearings. I

Also in the cases where the tailstocks areflxed l0 and relatively largering gears are-utilized it was necessary after moving thecrankshaft'into the chucking devices to lower it to the chucking membersand to raise it again after machining of the crankshaft before it wasremoved outwardly 16 from the ring gear chuck. This resulted inconsiderable effort on the part of the operator especially-when it wasdone manually. This also required considerable carefulness of operationon the part of the operator. Where loading devices 20 were used, whichloading devices were necessarily of elaborate construction to effectthese various movements mechanically, the operator had to carefullyactuate them in their proper sequence.

In instances where the tailstocks have been moved in the past the workwas invariably loaded manually or by use of the usual cable and hookcrane. Such loading and unloading was particularly diflicult ininstances where more than one center, drive chuck was used because ofthe inability to properly hold the crankshaft when threading it throughthe chucking devices. The result was that the ring gears had to be maderelatively large to permit the crank to be loaded manually withoutstriking the chucking mechanism, and also, the cutting tools had to bewithdrawn a relatively great'distance from the axis of rotation of thechuck so that they would not be struck by the crankshaft when soloaded'. This 40 method obviously was very cumbersome and extremelydifficult for the operator to perform and consuming considerable timeand energy on his part. Another defect of the above method was thatthere was no accurate way of guiding the crankshaft into and out of thechucking devices independent of the skill and effort exerted on the partof the operator.

In instances where the former type loading devices were used it wasfound that considerable effort was required on the part of the operatorhere developed, this former effort was substantially reduced to a.minimum while at the same time greatly reducing the amount of mentaleffort and skill necessary-on the part of the operator in actuating theformer loading devices in a definite sequential manner and inpractically eliminating all costly loading devices.

Furthermore, with these former methods including the former type loadingdevices, it was chuck whereas with the present method we are now able tosimultaneously eject the completed crankshaft from the center drivechuck while loading an unmachined shaft therein. And furthermore in theformer devices particularly where one device is utilized for loading andanother for unloading of the work, it was necessary for the operator tomove from one side of the machine to the other for operating therespective cranes which, of course, consumed time and effort on the partof the operator and cut down the productive output of the machine.

With these former difliculties clearly in mind, it is therefore anobject of our invention to provide means for easily loading andunloading crankshafts in a center drive lathe on the axis of rotationofthe center drive chucking devices and to provide means for ejecting saidcrankshafts from the chucking devices with a of effort on the part ofthe operator.

The chief aim of this invention is to provide suitable locating areas ornotches on the work piece or crankshaft adapted to be engaged by thechucking devices of a center drive lathe and to provide in conjunctionwith said chucking devices means, associated with the tool bars andtaflstocks of said lathe, comprising a substantially continuous railpassing through the center drive chucks and past the tailstocks to forma substantially continuous track upon which may be axially slid thecrankshaft upon its premachined locating notches for loading into andejection from said center drive chucking devices, this arrangement beingmore fully set forth in they above mentioned application Serial No.209,738. p

The problem ,of properly preparing a rough crankshaft forging or castingto meet the above requirements has indeed been diflicult. In the pastcrankshafts were made from a flat slab of cle clearly illustrates thesteps in the process that were formerly used. Obviously the webs ofthese crankshafts were generally rectangular and had had not beenpresent at this time.

With the development of the more general use of multi-throw crankshafts,particularly in the automotive field, this former method became obsoletein favor of the more rapid process of forging, and still later, castingprocesses. With the latter processes the webs of the crankshaft wereformed with very rough and irregular suringof crankshafts.

faces. ment of counterweighted webs to provide proper dynamic balancefor the high speed motors used today, has resulted in modem-daycrankshaft having extremely irregular and odd-shaped webs. Chucking suchtypes of crankshafts presents extreme dimculty particularly whenmultiple hearing turning, as required today, must be undertaken. I

The chucking of these modern-day crankshafts has been substantiallysolved by arrangements such as shown in Patents 1,843,359, 1,934,976,2,030,020, and 2,106,501. -However, the problem of loading and unloadingof the work or crankshaft in such arrangements has been lacking inefliciency commensurate with the high efliciency now obtained by thesearrangements in machin- Loading and unloading devices of a. charactershown in'Patents 1,700,721 and 2,069,107 have been used but theseinvolve costly apparatus and require considerable effort on the part ofthe operator to manipulate.

And not only this, but also the develop- An object of this invention isto provide a unique arrangement of locating notches on a crankshaftwhich serve both as the means for supporting and rotating the crankshaftin the lathe and as means for loading and unloading the crankshaft inthe chucking devices.

Another object is to prepare a crankshaft, for loading and unloading ina lathe, with a series of axially spaced locating notches in the roughwebs of the crankshaft, the 'notchesbeing radially positioned relativeto the axis of the crankshaft so as to define unobstructed angularlyrelated planes substantially parallel to said axis. The notches arearranged as guides upon which the crankshaft may be slid axially-into orout of the chucking devices of the lathe.

Furtherfeatures and advantages of this invention will appear in thefollowing detailed de-' scription of the drawings in which- Figure I isa perspective view of one side of a crankshaft with locating notchesarranged for loading and unloading the crankshaft in a lathe.

.Figure II is a perspective view of the other side of the crankshaft inFigure 1 showing a similar set of notches for loading and unloading thecrankshaft in a lathe.

Figure 111 is an end view of the crankshaft looking from the stub endtoward the flange end of the crankshaft.

The crankshaft here shown for illustrative purposes comprises the linebearings 21-, 28 and 29; the flange'end 30 and stub end 3|; the crankpins I, 2, 3, and l; and the interconnecting webs 5, 6, I, 8, 9, andI'll. .On one side of the crankshaft on the webs 5, 6, 9, and 10 areformed the locating notches 43, which are preferably arranged as shownin Figure III in planes parallel with the axis of rotation A of thecrankshaft. Similarly, locating notches '44 are formed on the webs 6, 9,and 10, preferably diametrically opposite the notches 43. Noting FigureIII it can be clearly seen that these notches form unobstructed groovesupon which may slide axially on a suitable loading and unloading railinto or out of a chucking device of a lathe; I

These same locating notches also provide the sole means for. supportingand rotating the chankshaft-in the lathe when turning the line bearingsand associated portions of the shaft. Usually the notches on the webs 6and 9 are sufficient for this purpose.

'The notches are also available for indexing and driving the crankshaft.when chucking in an orbital lathe for the turning of the crankpinaplurality of aligned and unobstructed grooves ex- In this instancethe notches 43 on the webs 5 and Ill are-utilized. v 7

Having set forth and described our invention what we claim as new anddesireto secure by United States Letters Patent is: I

l. A crankshaft blank prepared for loadin and unloading in a. machinetool, said crankshaft blank having notches formed on axially spaced websof said crankshaft blank so as to form a plurality of aligned andunobstructed grooves extending in a straight line axially the entirelength 0! said crankshaft blank upon which said crankshaft blank may beaidally slid in and out of a chucking device'oi said machine tool. 7

2. A crankshaft blank prepared for loadin and unloading in a machinetool, said shaft having notchesformed on its webs so as to form atending in a straight line axially the entire length of the crankshaftblank upon which said crankshaft blank may be axially slid in and out ofa chucking device of said machine tool.

3. A crankshaft blank prepared for loading and chucking in a machinetool, said crankshaft blank having loading and chucking notches formedon axially spaced webs so, as to form a plurality of aligned andunobstructed grooves extending in a straight line axially the entirelength of the crankshaft blank upon which said crankshaft blank may heslid axially in and out of a chucking device and for gripping saidcrankshaft blank by said chucking device.

. WILLIAM F. (ZilEtOElIlii.

WALTER R. MEYER.

